LRGV Improvements (AEPSC RPG 20150515)

LRGV Improvements (AEPSC RPG 20150515)

LRGV Area
Transmission
Improvements
ERCOT Regional Planning Group
May 19th, 2015
(Prepared by AEPSC)
LRGV Highlights
~890 MW Existing
1.3 GW Potential
AJO
(345 KV)
Internal
Valley
Constraints
NORTH
EDINBURG
Los Vientos I/II
& RedFish
(600 MW)
HEC
(458 MW)
MVEC
(670 MW)
RIO
HONDO
Frontera
(524 MW)
Railroad
HVDC Tie
(+/- 300 MW)
Silas Ray
(104 MW)
2
Study Drivers (1 of 2)
• Revised NERC TPL Standards
o Assessments Begin in 2015
o Enforcement Begins in January, 2021
o TPL-001-4 Performance Requirement P3 Includes G-1, G-1
• G-1: MVEC Combined Cycle Plant (678 MW) +
• G-1: HEC Combined Cycle Plant (463 MW)
o Non-Consequential Load Loss from P3 Event Must Not Exceed 75 MW
• Eliminates Usage of LRGV Under Voltage Load Shed (UVLS) Plan
• Loss of Local Generation
o Frontera is Exiting from the ERCOT Market to the Mexico Market
o Loss of 524 MW of LRGV Generation by Mid-2016
3
Study Drivers (2 of 2)
• Stability Limitations for Coastal (Ajo) Area Wind
o ~890 MW Wind (Available or in Final Stages of Construction)
o Wind Export Limitations:
• 580 MW (N-1 Conditions)
• 305 MW (N-1-1 Conditions)
o Additional Wind Under Study
o Existing SSCI Exposure
• Recent LRGV Load Shed Events
o February 2011 Load Shed Event (~300 MW)
o October 2014 Load Shed Event (~150 MW)
• G-1, G-1 Events
• Sustained High Rate of LRGV Load Growth
4
Study Prep and Objective
• Case Preparation Aligns with ERCOT’s 2014 Assessments
o Study Case: DWG 2018 Summer Peak Flat Start Case
o Case Updates: Alignment with Latest SSWG Cases
• Planned LRGV 345 kV System Improvements Included
o Frontera Plant: Unavailable
o LRGV Conventional Generation Dispatched at Full Output
o Wind Dispatch: 10%
o Railroad DC Tie: Neutral
o Voltage Schedule and Reactive Devices Set for High Pre-Disturbance LRGV Voltage Profile
• Study Objective(s)
o Identify LRGV Load Serving Capability for Existing System (Need Date Assessment)
o Compare Transmission Investment Value of ‘Layers’ of Potential Solutions
• MW/$M Basis
o Evaluate Alternative Source Location Solutions
o Ajo Area Wind Sensitivity:
• Evaluate incremental cost and capability of LRGV transmission plan to mitigate stability
limitations and SSCI concerns impacting Ajo Area Wind
o Future Generation Sensitivities:
• Identify Impact of Future Generation with IAs, but NOT Other PG Section 6.9 Criteria
• Quantify Generation Export Limitations for Existing System Under Light Load Conditions
o “RECOMMEND A LONG-TERM TRANSMISSION EXPANSION PLAN THAT WILL SUPPORT LRGV
LOAD LEVELS WELL BEYOND THE 10 YR PLANNING HORIZON”
5
Study Methodology
• LRGV ‘Study Area’ Comprised of Zones along with Interface
o
o
LRGV Load Busses Defined by Zones 610, 615, 800, 829, 875, and 876
LRGV Interface Composed of 3 - 345 kV lines and 3 - 138 kV lines
• Analyze Impact of Incremental Increases in LRGV Load
o
o
o
o
Increase LRGV Load in 100 MW Increments, Reapplying Contingency Conditions
Scale LRGV Load Using Constant P/Q Ratio
Capture Contingency Conditions and Corresponding Max LRGV Load Resulting in Acceptable
System Conditions (i.e. Identify the Limit)
Apply Analysis Methodology to Existing System and System with Alternative Solutions
• Quantify Results in Terms of ‘LRGV Load Serving Capability’
o
Enables Extrapolation of System Limits to Point-in-Time via Load Forecast Overlay
• Use NERC TPL-001-4 Criteria During Study Analysis
o Study Focuses on Long-Term LRGV Plan (Post 2021 Enforcement of TPL-001-4)
o Operation of UVLS Scheme is Not Acceptable
o Contingencies Tested Include: G-1+G-1, N-1-1, N-1+G-1, and G-1+N-1
• Assume G-1, G-1 to be Loss of Entire Combined Cycle Plants
6
LRGV 50/50 Load Forecast
2,424
2,599
2,552
2,621
2,522
2,598
2,482
2,502
2,374
2,467
2,334
2,288
2,382
2,261
2,300
2,330
2,400
2,428
2,500
2,530
2,600
2,458
2,700
2,568
50/50 Summer
Peak Forecast:
2,568 MW
2,642
50/50 Winter
Peak Forecast:
2,482 MW
2,800
2,675
Winter Peak MW
2,569
Summer Peak MW
2,200
2,100
2,000
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
7
LRGV 90/10 Load Forecast
2,771
3,014
2,737
2,993
2,715
2,958
2,691
2,911
2,660
2,883
3,049
90/10 Winter
Peak Forecast:
2,911MW
Winter Peak MW
2,621
2,843
2,592
2,784
2,556
2,737
2,516
2,468
2,414
2,652
3,000
2,684
90/10
Summer Peak
Forecast:
2,660 MW
3,500
2,500
Summer Peak MW
2,000
1,500
1,000
500
0
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
8
Existing System Results
• Existing Transmission System Can Support ~2,200 MW of LRGV Load
o Most Limiting Contingency:
• G-1+G-1 Loss of MVEC and HEC Plants
o System Limitation:
• Post Contingency Voltages in LRGV Fall Below 0.90 Per Unit UVLS Threshold
o AEP’s LRGV 50/50 Peak Load Forecast for Year 2021:
• Summer Peak: 2,598 MW / Winter: 2,482 MW
o AEP’s LRGV 90/10 Peak Load Forecast for Year 2021:
• Winter Peak: 2,911 / Summer: 2,660 MW
• Additional Facilities Required By Jan. 2021
o Existing LRGV UVLS Scheme May Shed Up To 30% LRGV Load and….
o Is a Clear Violation of 75 MW Non-Consequential Load Loss Limit Imposed by NERC TPL-001-4
Requirement “P3” for G-1+G-1 Conditions
o Improvements are Required to Maintain NERC Compliance
9
LRGV Historical Load
10
AEP’s Breakthrough Overhead
Line Design (BOLDSM)
BOLD Line Advantages:
 Lower Impedance
 Eliminates Need for Series Compensation
 No Added SSR/SSCI Risk to Area Generation
 Mitigates Operational and P&C Complexities
Associated with Series Compensated Lines
 Increased Capacity
 Comparable Cost to Traditional Series
Compensated 345 kV Transmission
*AEP Awarded Two Patents by U.S. Patent and
Trademark Office (Third Patent Pending)
11
Solution Options Evaluated (A)
(A) New Ajo – Caballo 345 kV
BOLDSM Transmission Lines
• Add two (2) new 345 kV terminals at
existing Ajo Station.
• Construct a new 345 kV switching station
(“Caballo”) near the existing Lon Hill North Edinburg 345 kV line ~13 miles west
of the Ajo Substation.
• Construct two new 345 kV dbl-ckt capable,
one ckt strung, transmission lines from
existing Ajo Station to the new “Caballo”
Station utilizing 3 x 954 ACSR (Cardinal)
conductor on BOLD lattice steel towers.
• Estimated Cost: $93.6 M
Caballo
Ajo – Caballo 345 kV
(Ckts 1 & 2)
Ajo
Zorillo /
Gulf Wind
12
Solution Options Evaluated (B)
San Miguel
(B) San Miguel – Lobo – North Ed.
345 kV 2nd Ckt with Series Comp.
San Miguel – Lobo
(Ckt #2)
Lobo
Cenizo/
Molina
Lobo – Cenizo –
Del Sol – North Edinburg
(Ckt #2)
• New 345 kV terminals at San Miguel, Lobo (2),
Cenizo (2), Del Sol (2) and North Edinburg.
• Install 24 ohm series capacitor at Cenizo with
bypass switching.
• Install 24 ohm series capacitor at Del Sol with
bypass switching.
• String 2nd Ckt on existing dbl-ckt capable
structures from San Miguel to Lobo, and
Cenizo to Del Sol to North Edinburg (~235
miles) utilizing 2 x 954 ACSR (Cardinal)
conductor.
• Convert Lobo to Molina 138 kV line to 345 kV
operation.
• Install two (2) 675 MVA, 345/138 kV autos
tying the Cenizo 345 kV and Molina 138 kV
stations.
• Estimated Cost: $293.8 M
Del Sol
North Ed.
13
Solution Options Evaluated (C)
Sarita/Penascal
Ajo
Zorillo /
Gulf Wind
Ajo – NSUBXING
345 kV (BOLD)
North Edinburg
NSUBXING
345/138 kV
Rio Hondo
S. Santa Rosa
(C) New Ajo – NSUBXING 345
kV BOLD Transmission Line
• Add a new 345 kV terminal at the existing
Ajo Station.
• Construct a new 345/138 kV station
(“NSUBXING”) west of the Rio Hondo
Station at a point near the crossing of the
east-west dbl-ckt North Edinburg to Rio
Hondo 345 kV and Rio Hondo to South
Santa Rosa 138 kV lines and the northsouth Raymondville to Harlingen 69kV
transmission lines. Cut-in the existing
North Edinburg to Rio Hondo 345 kV and
Rio Hondo to South Santa Rosa 138 kV
lines. Terminate the proposed 345 kV
BOLD line from Ajo. Install two (2)
675MVA, 345/138 kV autos.
• Construct a new 345 kV BOLD
transmission line from Ajo to NSUBXING
utilizing 3 x 954 ACSR (Cardinal)
conductor on dbl-ckt capable BOLD lattice
steel structures.
• Estimated Cost: $234.8 M
14
Solution Options Evaluated (D)
NSUBLH
Lon Hill
(D) New NSUBLH – Ajo 345 kV
BOLD Transmission Line
NSUBLH – Ajo 345 kV (BOLD)
Ajo
• Add a new 345 kV terminal at the existing Ajo
Station.
• Construct a new 345 kV switching station
(“NSUBLH”) ~1.5 miles west of the existing
Lon Hill Station, bisecting the Lon Hill to
Coleto Creek and Lon Hill to STEC Pawnee 345
kV transmission lines with cut-ins to the new
“NSUBLH” Station. Include a 345 kV terminal
for the proposed BOLD line to Ajo.
• Construct a new 345 kV BOLD line from the
new NSUBLH Station to the existing Ajo
Station utilizing 3 x 954 ACSR (Cardinal)
conductor on dbl-ckt capable BOLD lattice steel
structures.
• Estimated Cost: $218.1 M
Sarita/Penascal
Zorillo/Gulf Wind
15
Solution Options Evaluated (E)
NSUBLH
Lon Hill
• Construct a new 345 kV switching station
(“NSUBLH”) as introduced with Option
“D”. Include a 345 kV terminal for the
proposed BOLD line to NSUBXING,
instead of Ajo.
• Construct a new 345/138 kV station
(“NSUBXING”) as introduced with
Option “C”. Include a 345 kV terminal
for the proposed BOLD line to NSUBLH,
instead of Ajo.
• Construct a new 345 kV BOLD
transmission line from NSUBLH to
NSUBXING utilizing 3 x 954 ACSR
(Cardinal) conductor on dbl-ckt capable
BOLD lattice steel structures.
• Estimated Cost: $373.2 M
Ajo
NSUBLH – NSUBXING
345 kV (BOLD)
North Ed.
(E) New NSUBLH – NSUBXING
345 kV BOLD Transmission Line
NSUBXING
345/138 kV
Rio Hondo
16
Solution Options Evaluated (F)
Weslaco SVC
South McAllen
SVC
La Palma
SVC
(F) Installation of Static
Var Compensators (SVC’s)
• Install a +600/-200 MVAR SVC
at South McAllen
• Install a +600/-200 MVAR SVC
at La Palma
• Install a +400/-100 MVAR SVC
at Weslaco
• Estimated Cost: $175.4 M
17
Alternate Source Option (G)
Pawnee
Pawnee – NSUBXING
345 kV (BOLD)
New Pawnee to NSUBXING 345
kV BOLD Transmission Line
• Add a new 345 kV terminal at the
existing Pawnee Station.
• Construct a new 345/138 kV station
(“NSUBXING”) as introduced with
Option “C”. Include a 345 kV terminal
for the proposed BOLD line to Pawnee,
instead of Ajo.
• Construct a new single circuit 345 kV
BOLD transmission line from Pawnee to
NSUBXING utilizing 3 x 954 ACSR
(Cardinal) conductor on double-circuit
capable BOLD lattice steel structures.
• Estimated Cost: $486.6 M
Ajo
NSUBXING
345/138 kV
18
Alternate Source Option (H)
New San Miguel to NSUBXING
345 kV BOLD Transmission Line
San Miguel
San Miguel – NSUBXING
345 kV (BOLD)
• Add new 345 kV terminal at the existing
San Miguel Station.
• Construct a new 345/138 kV station
(“NSUBXING”) as introduced with Option
“C”. Include a 345 kV terminal for the
proposed BOLD line to San Miguel,
instead of Ajo.
• Construct a new single circuit 345 kV
BOLD transmission line from San Miguel
to NSUBXING utilizing 3 x 954 ACSR
(Cardinal) conductor on double-circuit
capable BOLD lattice steel structures.
• Estimated Cost: $487.7 M
Ajo
NSUBXING
345/138 kV
19
Initial Observations
• No Single Option Presented Above Yielded any Significant
Increase in LRGV Load Serving Value
• Two Existing System Limitations Impacting LRGV
o Broad LRGV Steady-State Low Voltage (2200 MW)
• Add SVCs
o Next System Limitation: Angular Stability for LRGV Import Conditions (2300 MW)
• Add New Transmission Paths
• Combinations of Options Presented Above Yielded Greatest
Increases in LRGV Load Serving Value:
o LRGV Reactive Support: Bolsters LRGV Voltage Profile
o New 345 kV BOLD Line: Improves Angular Stability
20
Option Performance
Comparison of Top Performing Improvement Options
Option
Incremental
Load Served
(MW)
Limiting
Contingency
Limiting
System
Condition
Estimated
Cost
($M)
Load Serving
Value
(MW/$M)
E+F
1300
HEC+MVEC
Voltage
$556.2(LC1)
2.3
C+D+E+F
1500
HEC+MVEC
Voltage
$695.0(LC7)
2.2
A+D+E+F
1500
HEC+MVEC
Voltage
$693.0(LC6)
2.2
C+D+F
1300
HEC+MVEC
Voltage
$621.5(LC2)
2.1
D+E+F
1300
HEC+MVEC
Voltage
$632.5(LC3)
2.1
A+E+F
1300
HEC+MVEC
Voltage
$649.8(LC4)
2.0
A+C+D+F
1300
HEC+MVEC
Voltage
$663.1(LC5)
2.0
*Ranked According to Incremental LRGV Load Serving Value (MW/$M)
Option Assignment Reference Table
Contingency Reference Table
Option A:
Option B:
Option C:
Option D:
Option E:
Option F:
Option G:
Option H:
MVEC = Magic Valley Combined Cycle Plant
HEC = Hidalgo Combined Cycle Plant
LH-NE = Lon Hill – North Edinburg 345 kV Line
RH-AJ = Rio Hondo – Ajo 345 kV Line
New Ajo – Caballo 345 kV (Two dbl-ckt BOLD lines)
San Miguel – Lobo – North Edinburg (2nd circuit)
New Ajo – NSUBXING 345 kV BOLD
New NSUBLH – Ajo 345 kV BOLD
New NSUBLH – NSUBXING 345 kV BOLD
SVC’s at South McAllen, Weslaco and LaPalma
New Pawnee – NSUBXING 345 kV BOLD
New San Miguel – NSUBXING 345 kV BOLD
21
Observations
• Top Performing Option (*Per Investment Dollar)
o




E+F = Direct Corpus to Valley 345 kV BOLD Line with LRGV SVCs
Increases LRGV Load Serving Capability: ~2,200 MW Increases To 3,500 MW
Supports Valley Well Beyond AEP’s 10-Year Valley Forecast: 50/50 or 90/10
Lowest Cost Option Amongst Best Performers ($556.2M)
Adds No New Export Paths from Ajo
22
Alternate Source Location
Comparison of BOLD Transmission Line “Source” Locations
Option
E+F
(NSUBLH)
F+G
(Pawnee)
F+H
(San Miguel)
Incremental
Limiting
Limiting
Load Served Contingency
System
(MW)
Condition
Estimated
Cost
($M)
Load Serving
Value
(MW/$M)
1300
HEC+MVEC
Voltage
$556.2
2.3
1300
HEC+MVEC
Voltage
$668.0
1.9
1300
HEC+MVEC
Voltage
$667.9
1.9
 Incremental LRGV load serving capability is basically neutral across BOLD line source locations.
 E+F (NSUBLH Source) has significantly lower line miles resulting in significantly lower cost.
Option Assignment Reference Table
Option A:
Option B:
Option C:
Option D:
Option E:
Option F:
Option G:
Option H:
New Ajo – Caballo 345 kV (Two dbl-ckt BOLD lines)
San Miguel – Lobo – North Edinburg (2nd circuit)
New Ajo – NSUBXING 345 kV BOLD
New NSUBLH – Ajo 345 kV BOLD
New NSUBLH – NSUBXING 345 kV BOLD
SVC’s at South McAllen, Weslaco and LaPalma
New Pawnee – NSUBXING 345 kV BOLD
New San Miguel – NSUBXING 345 kV BOLD
23
Ajo Wind Export (Analysis)
• Basecase: 2016 DWG HWLL
o Planned (ERCOT Endorsed) LRGV 345 kV Improvements In-Service
o Total Ajo Area Wind: 888 MW
o LRGV Upgrade Options Presented Above Not Included in Baseline Analysis
• Existing Ajo Area Wind Export Stability Limitations
o N-1-1 Export Limit: 305 MW (34%)
o N-1-1 Limiting Outage: Ajo – Rio Hondo & Lon Hill – Nelson Sharpe 345 kV
o System Condition: Unstable Post-Contingency Voltage Oscillations
• Wind Export Study Objective
o Identify Best Overall Solution for Improving
• LRGV Load Serving Capability
• Ajo Wind Export Capability
o Not Aimed at Resolving Voltage Oscillation Issue
• Separate Ongoing Studies for this Specific Issue
• 200 MVAR Synchronous Condenser Added to Model at Sarita
• Masks the Voltage Oscillation Issue to Identify Next Limiting Condition
24
Ajo Wind Export (Results)
Wind Export Capability (Existing System and Option Performance)
N-1 Limit
(MW)
Limiting
Contingency
Existing
System
580
Ajo-NS
C+D
1,788
Ajo-NS
200 MVAR SC
@ Sarita
(“SC”)
1,288
Ajo-NS
Control
Instability
614
A+SC
2,088+
N/A
N/A
1,788
C+D+SC
2,088+
N/A
N/A
1,488
A+E+SC
2,088+
N/A
N/A
1,788
A+C+D+SC
2,088+
N/A
N/A
2,088+
Option
Limiting
Condition
Voltage
Oscillations
Voltage
Oscillations
N-1-1 Limit
(MW)
305
988
Limiting
Contingency
Limiting
Condition
Ajo-RH
NS-LH
Ajo-NSUBLH
Ajo-NS
Voltage
Oscillations
Voltage
Oscillations
Ajo-RH
NS-LH
Control
Instability
CB-LH
Ajo-NS
Ajo-NSUBLH
Ajo-NS
CB-LH
Ajo-NS
Control
Instability
Control
Instability
Control
Instability
N/A
N/A
Option Assignment Reference Table
Contingency Reference Table
“SC”: 200 MVAR Synchronous Condenser at Sarita
Option A: New Ajo – Caballo 345 kV (Two dbl-ckt BOLD lines)
Option C: New Ajo – NSUBXING 345 kV BOLD
Option D: New NSUBLH – Ajo 345 kV BOLD
Option E: New NSUBLH – NSUBXING 345 kV BOLD
Ajo-RH: Ajo – Rio Hondo 345 kV (Ajo to South)
Ajo-NS: Ajo – Nelson Sharpe 345 kV (Ajo to North)
NS-LH: Nelson Sharpe – Lon Hill 345 kV
CB-LH: Caballo – Lon Hill 345 kV (Northern portion of
25
existing Lon Hill – North Edinburg line once bisected)
Wind Export (Observations)
• E+F Option (without A): Top Performer for LRGV Load
o Adds No Value to Ajo Area Wind Exports
o Provides No Additional Paths Out of Ajo (Wind Farms Radial to Series Cap Under N-1)
• Voltage Oscillation Issue Effectively Masked by Synchronous Condenser
o Next Stability Limitation, “Control Instability”, Reached at 614 MW Under N-1-1
• Options A and C+D: Add Ajo Export Paths, Increase Export Capability, Reduce SSR Risk
• Option C+D+F:
o Mid-Range Performer for Wind Exports per Transmission Investment Dollar; Better than Option A+E+F
o Lowest Incremental Cost Option Addressing Ajo Area Wind Exports
o Sufficient to Support Existing Wind (888 MW) + ~600 MW Future Wind
Comparison of Ajo Area Wind Export Improvement Options
Option
(all with “SC”)
Cost over Option
E+F ($M)
Increase in
Capability (MW)
Wind Export Value
(MW/$M)
A+C+D+F
107(LC3)
1,474
13.8
C+D+F
65(LC1)
874
13.4
A+E+F
94(LC2)
1,174
12.5
26
AEP Recommendation
• AEPSC Recommends ERCOT Endorsement of Option
C+D+F





LRGV Load Serving Capability: 3,500 MW
Ajo Area Wind Export Capability: >2,088 MW (N-1) / 1,488 MW (N-1-1)
One of Top Performing Options in Both Analyses
Lowest Cost Option Addressing Both Constraints
Optimal Solution Addressing LRGV Load Serving Capability and Ajo Area Wind
Exports
• Estimated Cost: $621.5M
27
Recommended Solution
NSUBLH
D: NSUBLH – Ajo
345 kV (BOLD)
Ajo
C: Ajo – NSUBXING
345 kV (BOLD)
F: Weslaco
SVC
F: South
McAllen
SVC
NSUBXING
345/138 kV
F: La Palma
SVC
28
Generation Sensitivity
(Valley Load Support)
• Same Basecase as Original LRGV Load Serving Capability Analysis
• Same LRGV Load Evaluation Methodology Employed
• Generation Added to Original Basecase Analysis
o Recently Executed Interconnection Agreements
• Coronado Ventures La Paloma EC: 785 MW Combined Cycle Facility
• STEC Red Gate: 225 MW Peaking Facility
• Duke Los Vientos III, IV, V: 200 MW per phase (600 MW Total) Wind
• LRGV Load Serving Impact: 2,200 MW Increased to 2,800 MW
o G-1+G-1 (MVEC & HEC) Still Poses Worst Case Contingency
o System Limitation is Post Contingency Low Voltages in LRGV
• What if we add LRGV SVCs on Top of Local Generation???
o LRGV Load Serving Capability is Increased from 2,800 MW to 3,300 MW
o Need Only West Valley (South McAllen) and Mid-Valley (Weslaco) SVCs
o Above 3,300 MW: Angular Instability is Limiting Condition for N-1-1 Loss of AJ – RH & LH - NE
29
Generation Sensitivity
(Valley Exports – Light Load)
• Purpose: Identify Operational Limits That May Exist Under Light Load
o What is the Export Limitation and Ability of Conventional LRGV Generation to Run at Full Output?
• Case Preparation:
o
o
o
o
o
Same Case Topology as Original LRGV Load Serving Capability Analysis
(*No Improvements)
Added Valley Generation with Recent IAs
LRGV Load: Scaled Down to ~1100 MW
(~40% of Peak Load Forecast in 2021)
LRGV Conventional Generation: Dispatched at Full Output
LRGV Wind: Start at 10%; Incrementally Increase WFs to Export Limit
• Results:
Basecase LRGV System Topology Supports Exports of ~1,900 MW
1,900 MW Measured as Summation of Flows Across LRGV Transmission Interface Facilities
Stability Limitation: “Unacceptable Power Swing Damping of LRGV Generation Facilities”
Limiting Contingency: N-1-1 Loss of…
• Lon Hill to North Edinburg 345 kV Line
• Mutually Coupled Del Sol to Cenizo 345 kV and Zapata to Lopeno 138 kV Lines
o North Edinburg – Rachal – Falfurrias 138 kV Line is Loaded to 109% Under These Conditions
o
o
o
o
30